The present invention is directed to a system separating sample fluid in a chromatography column and directing the effluent of the chromatography column to a point of use, or detection and analysis, particularly to a combination of a chromatography column and an interface for directing the effluent of the chromatography column into a mass spectrometer, and more specifically to a combination of a horizontal flow chromatography column and a moving belt interface therefor.
In a liquid chromatography system, a sample fluid is first injected into a separation column and is followed by flowing an elution fluid therethrough. The separation column contains or is packed with a separation matrix or medium, as is well known in the art, which interacts with the various components of the sample fluid to be separated, and are differentially eluted therefrom using different eluting fluids. The separation columns generally known in the art are of a cylindrical construction and the fluid flows axially through a separating medium bed retained in the column. As the sample and elution fluids pass through the separating medium bed, the constituents of the sample fluid travel through the separation medium at different rates due to their interaction with the separation medium. As a result, these constituents or components emerge separated (i.e., have different elution rates and times) in the effluent or outlet stream of the column. For high performance separations, the use of small particle size packings in long narrow columns has resulted in very high operating pressures.
More recently, this problem of high operating pressures was resolved by employing liquid chromatography columns which utilize a horizontal or radial flow of the fluids through the separation medium in the column, which results in an increased output and in a shorter time, using the same separation medium. Thus, higher flow rates at lower pressures can be achieved using this horizontal flow technique. The horizontal or radial flow liquid chromatography columns are described and claimed in U.S. patent applications Ser. No. 794,727 filed Nov. 4, 1985, now U.S. Pat. No. 4,627,918 and Ser. No. 869,295 filed June 2, 1986, now U.S. Pat. No. 4,676,898, each in the name of Vinit Saxena.
In many applications, it is desirable to analyze and identify the chemical composition of one or more of the components of the sample fluid separated in a liquid chromatographic column, either immediately or shortly thereafter, and more preferably at the same location. Such an analysis and identification may be carried out, for example, in a mass spectrometer. Mass spectrometers are well known for their capability for their sensitivity and accuracy in analyzing various chemicals, but they also have a requirement for a high vacuum environment, such as for example, 10.sup.-5 Torr. The separated fluids discharged from the liquid chromatography columns are, typically, at atmospheric or higher pressures. Various methods and means have been proposed for transporting the column effluent or discharge into the ion source of a mass spectrometer. One such prior known device is the moving belt interface. The fluid discharged from the liquid chromatography column, in addition to being transported to the ion source of the mass spectrometer, must be vaporized for effective ionization thereof and analysis in the ionization chamber of the mass spectrometer.
Various types of moving belt interfaces have been developed, each involving heating of the discharge fluid to vaporize and remove the solvent in the sample as the fluid discharge moves along a moving belt into the ion source of the mass spectrometer, and each providing vacuum locks to maintain the vacuum integrity of the mass spectrometer. While these prior moving belt interface approaches have been successful for certain types of chemicals, they have not been satisfactory in the analyses of certain other types of chemicals including polar, some biological compounds and complex mixtures of certain materials.
Recently, an improved moving belt interface has been developed which provides the capabilities of controlling the speed of the moving belt, controlling the angle at which the material from a source, such as a liquid chromatography column, is directed onto the belt, providing for heating of the material, most intensely only at the tip or end of the belt located within the ion source or any other suitable part of the mass spectrometer, and providing a multiple stage vacuum pumping system which produces the required drop in pressure from near atmospheric to a high vacuum, thereby maintaining the vacuum integrity of the mass spectrometer. This improved moving belt interface is described and claimed in copending U.S. patent application Ser. No. 904,953, , filed Sept. 8, 1986 in the name of Brian D. Andresen.
As greater efforts are now being directed to the field of biotechnology, particularly to more sophisticated methods of biological biomedical analyses, greater needs have arisen for faster, more accurate methods for separating the components of complex mixtures of chemical and biological compounds and for quickly analyzing and identifying such components, while also minimizing the costs of such analyses.
Therefore, it is an object of this invention to provide a means for economically separating the components in a sample fluid and rapidly transporting the same to a point of use or detection, analysis and identification in a mass spectrometer.
A further object of this invention is to provide a combined liquid chromatography column with a moving belt interface for transporting and preparing fluids separated in the column for substantially simultaneous analysis thereof in a mass spectrometer.
Another object of this invention is to provide a method and means for combining a chromatography column, using readily replaceable and/or disposable separation media, with a moving belt interface.
Another object of the invention is to provide a combined horizontal flow chromatographic column and a moving belt interface having the capability of controlling the deposition of materials eluted from the column onto a moving belt.
Another object of the invention is to provide a combined horizontal flow chromatographic column and a moving belt interface with a very short transfer line between the column and the moving belt.
Additional objects, advantages and novel features of the invention will be set forth in part in the description which follows, and in part will become apparent to those skilled in the art upon examination of the following or may be learned by practice of the invention. The objects and advantages of the invention may be realized and attained by means of the instrumentalities and combinations particularly pointed out in the appended claims.